Valves



July 8 1959 J. vl. FREUD 3,454,029

i VALVES Filed April 2, 1965 sheet of 4 30 42 2| Z4 K )J Um /4 i l i lr/K\/ A\ A@ 2| 35 34 43 55 60 40 22 4| 4 .-wl/frrss''gf'g'f INVENTOR HQJohnv. Fredd BY if/M@ my d ATTORNEYS J. V. FREUD July s, 1969 VALVESFiled April 2, 1965 Sheet INVENTOR ,J ohh V. Fredd ATTORNEYS A f f July8, 1969 1 FRDD 3,454,029

VALVES Filed April 2, 1965 Y sheet of 4 F l G 5 INVENTOR JOHN V. FRE DD@wmfi Wwffm United States Patent O "ice 3,454,029 VALVES John V. Fredd,Dallas, Tex., assgnor to Otis Engineering Corporation, Dallas, Tex., acorporation of Delaware Filed Apr. 2, 1965, Ser. No. 445,116 Int. Cl. Gd11/02; F161: 17/04 U.S. Cl. 137-112 13 Claims ABSTRACT 0F THE DISCLOSUREA valve system or apparatus having communication with two separatepressure zones or areas .and communicating with a third separate zone orarea, and closure means controlling flow between each of the separatedirst and second zones or areas and the third zone or area arranged toprevent fiow from either of said first and second zones or areas to theother of said first and second zones or areas, whereby the first andsecond pressure zones or areas are prohibited `from owing from one tothe other at all times. A valve for such system having first and secondports each communicating with a common third port, and valve closuremembers movable in response to fluid pressures in said ports toselectively open and close s'aid first and second ports to communicationwith said third while preventing flow from either of said first andsecond ports through the other of said first and second ports.

This invention relates to valves and more particularly relates topressure operated valves.

It is a principal object of this invention to provide a new and improvedvalve.

It is another object of the invention to provide a valve which isselectively operated by fluid pressure to position the valve for controlof iuid flow between selected groups of zones.

It is a further object of the invention to provide a valve connectableto at least three pressure sources with the 'first source beingselectively connectable with the second and third sources while thesecond and third sources are not connectable with each other.

It is another object `of the invention to provide a valve connectable tothree pressure sources and operable by the pressure of either the secondor third sources but not by the pressure of the rst source.

It is an additional object of the invention to provide a valveconnectable to three pressure sources and operable by the pressure ineither the second or third sources and when opened may be maintained insuch position by pressure from Veither the source which effected theopening or by the pressure of the first source irrespective4A of whetheror not liow is occurring through the valve.

It is a particularly important object of the inventipn to provide avalve connectable to at least three pressure sources and operable byonly the pressure in either of `two of the sources to move the valve toa position to communicate with the source which effected opening thevalve and the third source but which after opening permits holding thevalve open by the pressure of either source and allows fiow in eitherdirection between the communicating sources.

It is a still further object of the invention to provide an apparatusfor controlling fiuid fiow between one zone and either of two otherzones wherein a valve means is operable between one position forcontrolling iiow between first and second zones while closing off athird zone and another position for controlling the How between the rstand third zones while closing the second 3,454,029 Patented `July 8,1969 zone, the valve -being operable in response to a pressuredifferential between the second and third zones.

It is another object of the invention to provide uid fiow controlapparatus for interconnecting a first zone with either of two otherzones which includes plug type valves which are reciprocable betweenfour positions for controlling fiow between selected groups of the zonesand closing off all flow between the zones.

It is a further object of the invention to provide apparatus vforcontrolling fluid ow between a first zone and either of two additionalzones which includes a ball type valve element in the flow path leadingto each of the additional zones.

It is also an object of the invention to provide apparatus forcontrolling fluid iiow between a first zone and either of second andthird zones including a ball valve which is rotatable between twopositions for interconnecting either the first and second zones or therst and third zones.

Additional objects and advantages of the invention will be readilyapparent Ifrom the reading of the following description of a deviceconstructed in accordancewith the invention, and reference to theaccompanying drawings thereof, wherein:

FIGURE 1 is a longitudinal sectional view of a valve constructedaccording to the invention, showing the Valve in closed position with nofluid communication between the zones interconnected by the valve;

FIGURE 2 is a longitudinal sectional view of the valve of FIGURE lshowing the valve in one open position with communication betweeri rstand third pressure sources or zones;

FIGURE 3 is a longitudinal sectional view of the valve of FIGURE lillustrating the valve in a second open position providing communicationbetween the second and third pressure sources;

FIGURE 4 is a longitudinal sectional view of another form of the valveconstructed in accordance with the invention;

FIGURE 5 is a sectional view along the line 5 5 of FIGURE 4;

FIGURE 6 is a view in perspective of one of the ball valves and itsoperator assembly as used in the valve of FIGURE 4, showing the ballvalve in closed position as shown in FIGURE 4;

FIGURE 7 is a view similar to FIGURE 6 showing the ball valve rotated tothe open position;

FIGURE 8 is a diagrammatic representation of one of the ball valves andsurrounding tubular structure, such as the valve housing, showing therotation of the ball required to move the valve between closed and openpositions;

FIGURE 9 is a fragmentary longitudinal sectional view of the valve ofFIGURE 4 showing one of the ball valves in open position to permitcommunication between two of the flow conduits;

FIGURE l0 is a longitudinal sectional view of an additional form ofvalve in accordance with the invention, illustrating one of the ballvalves in open position and the other ball valve in closed position;and,

FIGURE l1 is a longitudinal view in section illustrating a still-further form of valve in accordance with the invention showing the ballvalve in one open position.

Referring to FIGURE 1 the valve 20 is shown connected to a first iiowconduit 21 leading to a first pressure source or zone, a second flowconduit 22 leading to a second pressure source or zone, and a third iiowconduit 23 leading to a third pressure source or zone. The valveincludes a housing 24 having a central flow passage 25 extendingtherethrough communicating with a lateral opening 30 to permit fluidcommunication with the conduit 23. On opposite sides of the lateralopening the valve housing is reduced in internal diameter and internallythreaded along the section 31 and the section 32. The valve seat body 33is threaded into the section 31 of the valve housing and provided with abore 34 surrounded by an annular seat surface 35 formed around the boreat the inward end of the body. The valve seat body 40 is threaded intothe section 32 of the valve body and provided with an internal bore 41surrounded by an annular valve seat 42 at the inward end of the body.

A dual reciprocable valve assembly 43 is positioned within the bore ofthe valve body between the valve seat bodies to cooperate with the valveseat surfaces 35 and 42 for controlling fluid flow through the valve.The valve assembly includes a valve rod 44 with head members 45 and 50secured on opposite ends. A valve element 51 is slidably disposed on thevalve rod `and provided with a conical surface 52 to cooperate with thevalve seat 35 for controlling ow between the bore of the valve housingand the bore 34 through the valve seat body 33. An O-ring 53 ispositioned within the internal annular recess 54 of the valve element 51to seal between the rod and the valve element against leakage along therod through the valve element. Another valve element 55 is slidablydisposed on the valve rod to control the iuid ow between the bore of thevalve housing and the bore 41 through the valve seat body 40. The valveelement 55 has a conical seat surface 60 which cooperates with the valveseat 42 to close oi fluid flow between the bore of the housing and thebore of the valve seat body. An O- ring 61 within the internal annularrecess 62 of the valve element 55 seals between the valve element andthe valve rod. A spring `63 around the valve rod biases the valveelements 51 and 55 away from each other toward the ends of the rod andthe valve seats.

The valve is shown in FIGURE 1 in the fully closed position in whichthere is no flow through the valve between any of the interconnectedzones. The valve assembly is movable by the pressure in the conduits 21and 22 from the position shown in FIGURE 1 to either of the positionsillustrated in the FIGURES 2 and 3. The valve cannot be moved from thefully closed position shown in FIGURE l by the pressure within theconduit 23. During operation, the valve will remain closed as in FIG-URE 1 with each of the valve elements positioned on its respective seatso long as the pressure within the conduit 23 and the bore 25 of thevalve housing remains greater than the pressure in both of the conduits21 and 22. In this position of the Valve there can be no fluidcommunication between the conduits 21 and 22 or between either of theseconduits and the conduit 23.

When fluid communication is desired between the conduits 22 and 23, thepressure within the conduit 22 is raised to a value in excess of thepressure within the conduits 21 and 23 to displace the valve element 55from the seat 42 to open the bore 41 into communication with the bore 25as illustrated in FIGURE 2. In order for the valve element to be movedfrom its seat the spring 63 is compressed and the valve rod slidesthrough the other valve element 51 with the end member 45 and a portionof the valve rod moving the farther into the bore 34. With the valveopened to the position shown in FIGURE 2 the pressure differentialbetween the bore 25 and the bore 34 acts on the cross section of thevalve rod through the O-ring 53 in the valve element 51 and so long assuch pressure differential exists, the valve assembly will remain in theopen position to permit uid flow in either direction between theconduits 22 and 30. Even if ow between the conduits 22 and 23 ceases,the valve will remain open so long as there is a pressure differentialbetween bores 25 and 34 to hold the valve in the position illustrated inFIGURE 2. When the pressure within the bore 25 decreases to a value atwlliCh. the pressure dilerential between the bore 25 and the bore 34acting on the valve rod is below the combined force on the rod of thepressure within the bore 34 and the compressed spring 63, the valveassembly will be returned to the position shown in FIGURE 1 with thevalve element 55 seating on the surface 42 to close the bore 41.

If fluid communication is desired between the conduits 21 and 23, thepressure within the conduit 21 is raised to a valve which will causesuch pressure acting through the bore 34 to displace the valve element51 from the seat 35 compressing the spring 63 and sliding the end member50 and the valve rod farther into the bore 41 as illustrated in FIGURE3. After the valve element 51 has been moved away from the seat 35 asshown in FIG- URE 3 the valve assembly will remain substantially in theposition illustrated so long as the pressure within the bore 25 is of asuflicient value that the force of the pressure acting across thesection of the value rod within the O-ring `61 exceeds the forceresulting from the pressure within the bore 41 together with the forceexerted by the spring 63. With the valve assembly in such open positioniluid may flow in either direction between the conduits 21 and 23 andthe valve assembly will continue to remain open even when iluid owceases so long as the pressure within the chamber 25 is of suicientvalue to hold the valve assembly in the position. shown.

Fluid communication may be established from both the conduits 21 and 22simultaneously into the conduit 23. The pressures in both the conduits21 and 22 are raised to levels substantially equal to each other andabove the pressure in the chamber 25. Both the valve elements 51 and 55are displaced inwardly along the valve rod from their respective seatsto permit simultaneous flow from both the conduits 21 and 22 through thechamber 25 into the conduit 23. It will be obvious, of course, that if apressure differential develops between the conduits 21 and 22, the valveelement controlling the ow vfrom the conduit having the lower pressurewill close. For example, if the pressure in the conduit 22 exceeds thepressure in the conduit 21 with -both valve elements open, the higherpressure in the conduit 22 will be transmitted into the chamber 25 tocause a pressure differential across the valve element 21 to force itback to its seat and close the bore 34. Flow will not therefore occurbetween the conduits 21 and 22 even if both valve elements are in openposition. It will therefore be obvious that for simultaneous ow fromboth the conduits 21 and 22 into the lconduit 23, the pressure in boththe conduits 21 and 22 must be maintained substantially equal to eachother.

The valve arrangement illustrated in FIGURES 1-3 has wide applicationwhere the objective is to selectively connect a rst pressure source withsecond and third pressure sources without communication between thesecond and third pressure sources. For example, in the production of oiltwo producing zones often are in communication with the same -well boreand it may be desired to have fluid communication between a conduit inthe well bore and each of the producing zones without encountering theproblem of communication between the two zones. By use of theillustrative valve structure treating fluids may be circulated betweenthe conduit 23 and either of two producing zones which might `beconnected with the conduits 21 and 22 without encountering the problemof mixing the fluids in the zones connected with the conduits 21 and 22.

Another valve constructed according to the invention is illustrated inFIGURES 4-9. Referring to FIGURE 4 the valve y is enclosed in thehousing 71 which is connected to conduits 72, 73, and 74. The valvepermits fluid communication between the conduit 74 and either of theconduits 72 and 73 but not directly between the conduits 72 and 73. Thevalve assembly is retained in the housing between the internal annularshoulder 75 formed in the housing against which one end of the assemblyrests and the internal annular retainer ring threaded into the housingat the other end of the assembly. The valve includes an annular operatorpiston 81 slidably disposed within the valve housing to enclose andoperate the ball valve elements in response to pressure changes in theseveral conduits connected to the valve. The operator piston issupported at opposite ends around the tubular shaped valve seat bodies82 and 83 which cooperate with the central dual valve seat body 84 torotatably support the ball valve elements 85 and 90. The valve seatbodies 82 and 83 are threaded into the end seal assemblies 91 and 92,respectively, which support the valve and seal with the inner wall ofthe housing at opposite ends of the valve.

The annular piston heads 93 and 94 are threaded into the opposite endsof the operator piston around the valve seat bodies 82 and 83,respectively. An O-ring 95 in the internal annular recess 100 within thepiston head 93 seals between the piston head and the external surface ofthe tubular valve seat body 82. An external annular flange 101 is formedaround the inward end of the valve seat body 82 within the operatorpiston to engage the inner wall of the piston. O-ring 102 within theexternal annular recess 103 around the flange seals between the flangeand the inner wall of the piston. The inward end 104 of the piston headand the outer shoulder 105 on the flange 101 cooperate with the outersurface of the valve seat body 82 and the inner surface of the piston toform an annular variable volume cylinder 110. A plurality of ports 111through the wall of the valve seat body connect the annular cylinderwith the bore 112 of the valve seat body. An annular valve seat surface113 is formed on the inward end of the valve seat body around the bore112 to seat against the ball valve 85.

The annular piston head 94 is threaded into the other end of theoperator piston around the valve seat body 83. The O-ring 114 in theinternal annular recess 115 of the piston head seals between the outersurface of the valve seat body and the piston head. The external annularflange 120 is formed around the inward end of the valve seat body 83 andprovided with an external annular recess 121 in which the O-ring 122 ispositioned to seal between the flange and the inner wall of the operatorpiston. The shoulder 123` on inward end of the piston head 94 cooperateswith the shoulder A124 on the outer end of the ange 120 and the outerwall of the valve seat body and the inner wall of the operator piston todefine the variable volume annular cylinder 125. A plurality of ports130 through the valve seat body into the annular cylinder provide fluidcommunication between the cylinder and the bore 131 of the valve seatbody. An annular valve seat surface 132 is formed around the bore 131 onthe inward end of the valve seat body to seat against the ball valve 90.

The central valve seat body 84 is supported between the ball valves 85and 90 by engagement of the annular seat surface 133 with the valve 90and with the annular seat surface 134 on the annular cap 135 with theball valve 85. The cap 135 is threaded over one end of the central valveseat body to facilitate assembly of the valve structure. The ball valve85 is rotated by the operator assembly 140 including the operator arms141 each of which has an operator knob 142 engaging one of the holes 143in the ball valve to rotate the bore 144 of the ball valve between theclosed position illustrated in FIGURES 4 and 6 and the open positionshown in FIGURE 7. The operator arms 141 extend from the base ring 145which is slidably engaged around the central valve seat body and biasedaway from the ball valve by the spring 150 disposed around the bodybetween the base ring and the shoulder 151 on the annular cap 135. Theball valve is thus biased toward a closed position by the spring. Asillustrated in FIGURE 5 the two operator arms 141 are supported from thebase ring spaced apart from each other approximately 120 degrees aroundthe ring to correspond with the spacing of the operator holes 143 in theball valve. As will be explained in more detail in connection with theoperation of the ball valve the operator knobs must move laterally orcircumferentially a small distance as well as longitudinally to rotatethe ball valve between open and closed positions. Therefore, theoperator arms are slender and sufficiently flexible to permit the smalllateral movement required of the operator knobs.

The ball valve is rotatable to move its bore 152 between open and closedpositions by engagement of the operator knobs 153 in the operator holes154 through the valve. The operator knobs are formed on the operatorarms 155 extending from the base ring 160 which is slidably disposedaround the valve seat body 83 and biased away from the base ring by thespring 161 to urge the valve toward a closed position. The spring 161 isconfined between the external annular shoulder 162 on the valve seatbody and the outer face of the base ring 163. The base ring along withits associated operator arms and knobs forms an operator assembly 164which is structurally and functionally the same as the operator assembly140.

Al plurality of radially spaced ports 165 extend through the centralvalve body 84 substantially along the middle of the body to permit thefluid communication from the bore of the body into the operator piston..An internal annular flange 171 is formed within and along the center ofthe operator piston and provided with a plurality of radially spacedports 172 to permit fluid to flow from within the operator pistonthrough the piston wall. The annular flange 171 forms an internalannular shoulder 173 which is engageable with the base ring 145 of theoperator assembly 140 and an internal annular shoulder 174 engageablewith the base ring 160 of the operator assembly 164. Rcciprocation ofthe.` operator piston 81 causes engagement between its internal annularflange and one of the base rings of one of the operator assembliesdepending upon the direction of reciprocation to effect rotation of oneof the ball valves.

The end support and seal assembly 91 includes an annular cap 175 havingan external packing recess 180 in which is disposed the packing 181 heldin place by the threaded retainer ring 182. 'Ihe assembly 91 supportsone end of the valve and seals around the valve with the inner wall ofthe housing 71. The other end of the valve is supported by the assembly92 which includes the annular cap member 183 having an external packingrecess 184 in which the packing 185 is positioned to seal with the innerwall of the housing 71. The packing is held ou the cap by the threadedretainer cap 190. The space between the end assemblies 91 and 92 aroundthe operator piston and the valve seat bodies defines the annularchamber 191 through which fluid flows from within the operator pistontoward the conduit 74.

In operation, the valve 70 is connected to the conduits 72, 73 and 74with the objective being to selectively provide fluid communicationbetween the conduit 74 and either the conduit 72 or 73 as desired. Withthe ball valves 85 and 90 positioned as illustrated in FIGURE 4 thevalve is considered as fully closed with no fluid communication from theconduit 74 to either of the conduits 72 and 73 or between the conduits72 and 73 themselves. Pressure increases within the conduit 74 to levelsin excess of the pressure within the other two conduits will not affectthe position of either of the ball valves, leaving them closed asillustrated. The pressure within the conduit 74 is exerted throughoutthe annular chamber 191 and through the openings 172 and 165 into boththe operator 4piston and the central valve seat. body thus contactingthe surfaces of both of the ball valves except for that portion of thevalve 85 exposed to the bore 112 and of the valve 90 exposed to the bore131. The net effect of the greater pressure within the operator pistonupon each of the ball valves is to urge the valves 85 and 90 intotighter sealing engagement with the seats 113 and 132 respectively.

If fluid flow is desired between the conduit 73 and the conduit 74, thepressure within the conduit 73 is raised to a level higher than thepressure in the conduit 72. The pressure in the conduit 73 iscommunicated through the openings 130 into the annular cylinder 125. Thepressure from within the conduit 74 is ineffective to move the operatorpiston as it is applied completely around the operator piston 81 betweenthe seals 181 and 185 within the annular chamber 191 and also throughthe ports 172 and 165 to the interior of both the operator piston andthe central valve seat body. The lower pressure from the conduit 172 isapplied through the openings 111 into the annular cylinder 110. Thehigher pressure from the conduit 73 is within the cylinder 125 while thecylinder 110 is exposed to the lower pressure within the conduit 72.There is, therefore, a tendency for the cylinder 110 to be reduced involume by movement of the operator piston upwardly. This sliding actionof the operator piston may be considered to be brought about by theforce of the higher pressure upon the outer end of the piston head 93which is opposed only by the lower pressure from the conduit 72 beingexposed to the inner face 104 of the piston. As the operator piston 81moves upwardly the shoulder 174 around the internal flange 171 of thepiston engages the base ring 160 moving the operator members 155 towardthe ball valve causing the operator knobs on the members to rotate theball valve from the closed position shown in FIG. 4 to the open positionillustrated in FIGURE 9. During the movement of the operator pistonupwardly the ball valve 85 remains in the closed position since theshoulder 173 on the internal flange of the piston moves away from thebase ring 145 thus not contacting the operator assembly for the valve.

As the operator assembly 164 moves toward the ball Valve 90, the -valVeis moved from the position illustrated in FIGURES 4 and 6 to theposition as shown in FIG- URES 7 and 9. While the FIGURES 5-8 arepresented in terms of the lower valve 85 and its related structure, itwill be understood that the upper valve 90 and its operator assembly areidentical in all respects to the lower valve mechanism. The perspectiveviews of FIGURES 6 and 7 along with the FIGURE 8 best illustrate themovement of the operator assembly and the ball valve as the valve isrotated from the closed to the open position. The operator knobs, asshown in FIGURE 5, are spaced circumferentially substantially 120degrees apart. As the operator members move the ball valve between openand closed positions rotating the valve the 90 degrees required toeffect such movement, each of the operator holes in the ball valvefollows the arcuate path shown by the dotted lines in FIGURE 8. As eachof the operator holes follows the arcuate path shown, the operator knobengaged in the operator hole, in order to rotate the ball valve, moveslongitudinally the distance L and oscillates a distance C around thecircumference of the ball valve as `diagrammatically represented inFIGURE 8. `It will be seen, therefore, that the operator members aresufficiently flexible to tolerate the lateral or circumferentialmovement the distance C to permit the operator knobs to follow thisarcuate path of the operator holes in the ball valves in order to rotatethe ball valves between the closed and the open positions.

With the ball valve 90 moved to the open position illustrated in FIGURE9, flow may take place between the conduits 73 and 74 through the pathdefined lby the bore 131 in the valve seat body 83, the bore 152 of theball valve 90, the bore 170` of the central valve seat body, the ports165 and 172 of the central valve seat body and operator piston,respectively, and into the annular space 191 around the operator pistonto the conduit 74. While the longitudinal displacement of the operatorpiston in moving the ball valve 90 to the open position shown in FIGURE9 results in misalignment of the ports 165 and v172, as illustrated, thefluids flowing through the ports 165 move into the annular space betweenthe central valve body and the operator piston and flow from suchannular space through the ports 172 to the exterior of the annularpiston. So long as the pressure within either the conduit 73 or 74 ismaintained at a level sufficiently above the pressure within the conduit72 the valve will remain in the open position of FIGURE 9 and flow mayeither be terminated or may occur in either direction between theconduits 73 and 74. It is again emphasized that while the valve cannotbe opened in either direction by an increase in pressure within theconduit 74, the valve may be held open -by the pressure in the conduit74 after having been opened by a pressure increase in either of theconduits 72 and 73. For example, if the valve is opened by the pressurein the conduit 73 with the pressure relationship then being shifted withllow occurring from the conduit 74. The higher pressure from the conduit74 will be applied in the cylinder 125 to hold the operator pistonupwardly and the valve open.

The lball valve 90y is closed by lowering the pressure within theconduits 73 and 74 to a level which permits the force of the spring 161to return the operator piston to the neutral position shown in FIGURE 4.Also the pressure in the conduit 72 may be raised above the conduits 73and 74 to effect the same results. As the spring moves the operatorassembly 164 toward the center of the valve, the inward end of the baserange 160 engages the internal annular shoulder 174 forcing the operatorpiston back toward the neutral position. This movement of the base ringof the operator assembly causes the operator knobs 153 to rotate theball valve 90 `back to the closed position illustrated in FIGURE 4. Withthe ball valve 90 returned to the closed position the valve is onceagain fully closed with communication being prevented between theconduit 74 and either of the conduits 72 and 73 and also between theconduits 72 and 73 themselves.

vIf fluid communication is desired between the conduits 74 and 72 thepressure within the conduit is raised to a level above the pressure inthe conduit 73 sufliciently to displace the operator piston downwardlyto rotate the ball valve to the open position. The procedure of openingthe ball valve y85 is identical to the opening of the ball valve 90. Anincrease in the pressure in the conduit 72 is applied through the bore112 and the ports 111 into the annular cylinder 110. The pressure in thecylinder is now higher than the pressure in the cylinder 125. Allsurfaces exposed to any pressure from the conduit 74 are equal andopposite surfaces and thus the pressure from the conduit 74 cancels outand is not effective to move the operator piston. The higher pressure inthe cylinder 110 acting against the lower pressure Within the cylindertends to diminish the size of the cylinder 125 and increase the cylinder110 causing the operator piston to move downwardly effecting engagementof the annular shoulder 172 within the operator piston with the basering of the operator assembly 140 to move the operator members andoperator knobs 142 rotating the ball valve 85 from the closed positionshown in FIGURE 4 to the open position. When the ball valve is open,fluid may flow from the conduit 72 through the bore 112, the bore 144 inthe ball valve, the bore 170 and the ports and 172 through the centralvalve seat body and the operator piston, respectively, into the chamber191 and to the conduit 74. So long as the pressure within either of theconduits 72 and 74 is maintained higher than the pressure in the conduit73 the valve will remain open. The pressure relationships may 'beadjusted so that a condition of either no flow or flow in eitherdirection may be maintained through the valve between the conduits 72and 74. If the pressure in the conduits 73 and 74 are equal and higherthan in the conduit 72, the valve 90 will remain open with no flow. Ifthe pressure in the conduit 74 is higher than 72 and 73, the valve willremain open with flow from the conduit 74 to the conduit 73. The valveis again returned to closed position when desired by lowering thepressures in the conduits 72 and 74 sufliciently to lower the pressurein the cylinder 125 to a level relative to the cylinder 110` for thespring 150 to expand drawing the ball valve 85 back to the closedposition and returning the operator piston again to the neutralposition.

The procedure of opening the ball valves in the valve of FIGURES 4-9 maybe varied by use of different pressure relationship from those describedabove in order t bring about the necessary longitudinal movement of theoperator piston. For example, if the ball valve 90 is to be opened thepressure within the conduit 72 may be lowered to a level below thepressure within the conduit 73 so that the pressure within the annularcylinder 125 will exceed the pressure within the annular cylinder 110 tocause the higher pressure within the cylinder 125 to force the operatorpiston upwardly. The net effect of this procedure is identical to thosepreviously described but is merely effected by lowering a pressure inone conduit as distinguished from raising the pressure in anotherconduit.

When a ball valve at one end of the valve of FIGURE 4 is open, thepressure within the two conduits in communication and thus through theopen portion of the valve is greater than the pressure within the closedconduit and therefore the other ball valve leading to the closed conduitis biased against the seat around the bore of the valve body leading tothe closed conduit to more effectively seal between the ball valve andsuch seat. For example, if the conduits 73 and 74 are in communicationby virtue of ball valve 90 being open the pressure within the bore 170will exceed the pressure within the bore 112 causing the ball valve 85to be urged more tightly against the seat 113 as the pressure within thebore 170 increases. It may therefore be seen that some flexibility may`be permitted in the construction of the valve with respect to thetolerances of the various parts including the ball valves and theirrespective seats as the pressure will tend to urge the ball valves moretightly against the seats through which there is a tendency towardleakage and therefore surface irregularities in the ball valves andseats may be compensated for by the biasing effect of pressure withinthe valve.

Another valve constructed in accordance with the invention isillustrated in FIGURE 10. The valve 200 controls fluid iiow between theconduit 201 and either of the conduits 202 and 203. As in the case ofthe previously discussed valves, the conduit 201 may be in communicationwith either of the other conduits but not both at the same time whilethe conduits 202 and 203 do not communicate with each other. A tubularhousing 204 is supported within the conduits between the seal assemblies205 and 210. The assembly 205 includes a seal mandrel 211 threaded intothe housing and having an external annular recess 212 in which the sealassembly 213 is retained by the retainer ring 214. Threaded into theother end of the tubular housing is the seal assembly 210 which includesthe seal mandrel 215 which is provided with an external annular recess220 in which is positioned the seal assembly 221 held by the retainerring 222. A fishing neck 223 having an external annular flange 224 isformed on the seal mandrel to facilitate insertion and removal of thevalve through the conduit 203. The seals 212 and 221 seal with the innersurface of the conduits 203 and 202 to define an annular space 225within the conduits around the tubular housing. A lower valve seat body230 threaded into the mandrel 211 extends into the tubular housing andis provided on its inward end with an annular valve seat surface 231around the bore 232 through the body. The external annular flange 233 isformed around the inward end of the valve seat body providing an annularshoulder 234. An annular piston 235 is slidably disposed around thevalve seat body Vwith an O-ring 240 in the internal annular recess 241within the piston sealing between the outer surface of the valve Seatbody and the inner surface of the piston. The O-ring 242 within theexternal annular recess 243 around the piston seals between the outersurface of the piston and the inner surface of the tubular housing 204.The annular cylinder 244 is defined by the inner wall of the housing,the outer wall of the valve seat body, the inward end of the mandrel 211and the outward end of the piston 235. The cylinder 244 and the bore 232are connected through a plurality of ports 245 radially positionedaround and extending through the wall of the valve seat body.

An external annular recess 250 is formed around the inward end of thepiston 235.

At the other end of the valve, the upper' valve seat -body 251 isthreaded into the upper seal mandrel 215 projecting 1nto and concentricwith the tubular housing 204. The inward or lower end of the valve seatbody is provided with an annular valve seat surface 252 around the bore253 through the body in alignment with the bore 254 through the mandrel215. An external annular flange 255 around the lower end of the body 251provides a shoulder 260 around the body. The annular piston 261 iSslidably positioned around the valve seat body within the tubularhousing with the O-ring seals 262 and 263 positioned in the annularrecess 264 and 265 respectively, to seal between the piston and theexternal surface of the valve seat body and the internal surface of thetubular housing. The inward ends of the mandrel 215, the outward end ofthe piston 261, the inner surface of the tubular housing, and the outersurface of the valve seat body define an annular cylinder 270 whichcommunicates with the bore 253 through a plurality of radiallypositioned ports extending through the wall of the valve seat body. Theinward end of the annular piston 261 is provided with an externalannular recess 272.

The ball valves 273 and 274 are held on the valve seats 231 and 252,respectively, by the central valve seat body 275. The annular sealsurface 280 around the lower end of the central valve seat body alongwith the seat surface 231 supports the ball valve 273. The annular valveseat surface 281 on the upper end of the central 'body and the seatsurface 252 support the ball valve 274. The ball valves are linked witheach other and with the pistons 235 and 261 by the operator members 283which extend between and engage the recesses 250 in the piston 235 and272 in the piston 261. The operator members are connected to the ballvalves by the operator knobs 284 and 285 which engage the operator holes290 and 291 in the ball valves 273 and 274, respectively. Each of theball valves has two operator holes spaced apart substantially degrees aspreviously discussed in connection with the valve 70 illustrated inFIGURE 4. Two operator members 283 are employed to interconnect the ballvalves with each other and with the annular pistons 235 and 261 so thatthe pistons may rotate the ball valves between open and closedpositions. The operator holes in the ball valves are alignedlongitudinally so that the two operator members extend substantiallyparallel to the longitudinal axis of the tubular housing and to eachother spaced apart as shown in FIGURE 5 so that the operator members mayfunction as those of the valve of FIGURE 4 in moving through thelongitudinal and circumferential paths followed by the operator knobs inrotating the ball valves between their open and closed positions. Fluidmay flow through the bore 282 of the central valve seat body, throughthe radially positioned ports 293 into the housing, and through theports 294 of the housing to permit fluid communication into the annularspace 225 from the ball valves.

It will be obvious that since common operator members are employed foractuating both of the ball valves and thus the ball valves are rigidlyinterconnected with each other they must move simultaneously. Itistherefore necessary in order to interconnect the conduit 201 with eitherthe conduit 202 or 203 and prevent the conduits 203 and 202 fromcommunication with each other that the ball valves be positioned out ofphase so that one is closed while the other is open. As illustrated inFIGURE 10, the ball valve 273 is open permitting communication betweenthe conduits 201 and 203 while the ball valve 274 is closed. When theball valve 274 is opened by the operator members, they Will close thevalve 273. To insure that the valves do not linger between positions andthus move between completely open and completely closed positions, eachof the annular pistons is provided with a detent assembly, piston 235with a detent assembly 295 and piston 261 with detent assembly 300.

Referring to FIGURE the detent assembly 295 includes a plurality ofoutwardly extending radially spaced collet lingers 296 -formed aroundthe piston 235. The collet lingers are laterally flexible so that theymay be expanded and contracted radially for locking and unlocking thepiston 235 at the extreme downward end of its stroke. Each of the colletfingers is provided with an inwardly extending boss 297 to engage thesplit ring 298 disposed around the valve seat body in the externalannular recess 299 to provide a locking flange for the collet lingers.As the piston moves downwardly to the bottom end of the stroke thecollet lingers spring outwardly and around the split ring with thelingers retracting inwardly when the bosses have passed the split ring.The bosses engage the lower surface of the split ring to hold the pistonin its lowermost position until the pressure within the cylinder 244 issuliciently high to push the piston with adequate force to cause thecollet lingers to spring outwardly and disengage the split ring allowingthe piston to move upwardly. The pressure at which the collet lingersdisengage is high enough that when the collet fingers unlock the pistonthe piston will move the ball valves completely between positions sothat the valves are not left in a partially open or closed condition.The detent assembly 300 at the other end of the valve includes thecollet lingers 301 formed on and extended outwardly from the annularpiston 261. The collet lingers have the inwardly projecting bosses 302which releasably engage the split ring 303 positioned in the externalrecess 304 around the valve seat body 251. The collet lingers arelaterally flexible so that when the piston moves to the upper end of itsstroke the collet lingers will spring outwardly with the bosses slidingover the split ring to again spring inwardly when the bosses have passedthe split ring as shown in FIGURE 10 to lock the piston to the splitring at the upper end of its stroke. When the pressure within thecylinder 270 is raised to the desired predetermined level for moving thevalves completely between open and closed position the collet lingerswill disengage to permit the piston to be displaced downwardly.

The valve 200 is moved between the position connecting the conduits 1with 203 and the position connecting the conduits 201 and 202 by theaction of the pressure from the conduits on the annular pistons 235 and261. For example, in order to close the valve 273 and open the Valve 274to place the conduits 201 and 202 in communication, the pressure israised within the conduit 202 to a level sulciently in excess of thepressure in the conduits 201 and 203 to cause the higher pressure withinthe conduits 202 to be applied through the ports 271 into the annularcylinder 270 to displace the piston 261 downwardly. The lower cylinder244 is exposed to the lower pressure of the conduits 203 and 201 throughthe port 245 while the upper cylinder is exposed to the higher pressureof the conduit 202 through the port 271. When the pressure within theconduit 202 is raised sufficiently, the piston 261 is forced downwardlyto rotate the ball valve 274 to the open position while rotating theball valve 273 to the closed position. Since the inward ends of theannular pistons 235 and 261 are both exposed to the same liuid pressurewithin the tubular housing 204 the only pressure differential beingimposed across the annular pistons is within the annular cylinders whichare each exposed to the pressure within the conduits at the oppositeends of the valve and thus the higher pressure within one conduit suchas 202 within the annular cylinder at that end will displace thatcylinder and the operator members toward the ball valves since thatpiston is interconnected with the piston at the other end which isexposed to the lower pressure of the other conduit. In order to insurethat the ball valves will move completely from one position to anotherposition and thus avoid lingering between open and closed positions, thedetent assemblies on each of the annular pistons are adjusted to retaineach piston until the pressure within its respective cylinder is builtup to a sufficiently high level to displace the piston the requireddistance to fully close one ball valve and open the other. For example,in moving the valve from the position of FIGURE 10l to the position inwhich the ball valve 274 is Open and 273 is closed, the detent assembly300 holds the piston 261 in the position illustrated until the pressurewithin the annular cylinder 270 is high enough that upon release thepiston will immediately move the full length necessary to fully open thevalve 274 and fully close the valve 273. As in the case of the otherforms of valves previously discussed, the embodiment of FIGURE l0 is notoperable in response to the pressure within the conduit 201 but ratheroperation must be initiated by a pressure differential between theconduits 202 and 203. Once, however, the valve is in a given openposition a condition of flow in either direction or no liow may existbetween the two particular conduits which are in communication so longas the pressure in either or both of the communicating conduits is abovethe pressure in the closed conduit.

A still further form of valve constructed according to the invention isillustrated in FIGURE 1l wherein a single ball Valve is rotatablebetween two positions to selectively place one zone in communicationwith one of two other zones. Referring to FIGURE ll, the valve 310 ispositioned within the conduits 311 and 312 which are interconnected withthe conduit 313. The tubular valve housing 314 is supported at theopposite ends by the seal assemblies 315 and 320. The assembly 315includes a seal mandrel 321 with an external annular recess 322 for thepacking assembly 323 to seal with the inner wall of the conduit 311. Thepacking assembly is secured on the mandrel by the retainer ring 324. Theseal assembly 320 includes the seal mandrel 325 which supports thepacking assembly 330 in the annular recess 331 to seal between the endmember and the inner surface of the conduit 312. The packing assembly isheld on the mandrel by the annular retainer ring 332. A fishing neck 333having an external annular ange 334 is formed on the end member topermit the connection of a suitable running and pulling tool with thevalve.

The valve seat bodies 335 and 340 are threaded into the seal mandrels321 and 325, respectively, and extend toward each other within thetubular housing. The ball valve 341 is supported by the valve seatbodies between the annular seat 342 on the body 335 and the annular seat343 on the body 340. The L-shaped flow passage 344 through the ballvalve allows fluid liow from either the bore 345 through the body 33S orthe bore 350 through the body 340 into the annular space 350a around thevalve seat bodies. Fluid may then liow through the ports 351 in thetubular housing 314 into the conduit 313. The ball valve isinterconnected with the annular pistons 353 and 354 by the operatormembers 352. The operator balls 355 on the operator members lit into theoperator holes 360 within the ball valve. The operator members areengaged at opposite ends into the annular recesses 361 around the inwardend of the pistons 353 and 362 around the inward end of the piston 354.The ball valve 341 has two operator holes spaced approximately degreesapart in which are engaged the operating knobs of two operator members.The movements of both the ball valve and the operator members inrotating the ball valve between open and closed positions are identicalto the movements of the corresponding members of the `other ernbodimentsof the valve previously discussed.

The O-ring 363 in the annular recess 364 seals between the piston 353and the seat body 335 Iwhile the O-ring 365 in the recess 370 sealsbetween the piston and the housing 314. The O-ring 371 in the internalannular re- `cess 372 of the annular piston 364 and the O-ring 373 inthe recess 374 of the piston seals betweenthe piston and the seat body340 at the housing 314, respectively.

An annular cylinder 37-5 is defined by the valve seat body 335 and thetubular housing between the inward end of the seal mandrel 321 and theouter end of the piston 353. The cylinder 375 is connected with the bore345 by the port 376 through the seat body. A detent assembly 380detachably engages the annular piston 353 at the outward end of itsstroke to insure movement of the ball valve from the fully closed to thefully open position.

At the other end of the valve the outward end of the annular piston 354with the inward end of the seal mandrel 325 and the i-nner surface ofthe tubular housing and the outer surface of the valve body 340 formanother annular cylinderf390 which is in fluid communication with thebore 345 through the radially positioned ports 391 through the valveseat body. A detent assembly 392 detachably engages the annular pistonwith the valve seat -body until a predetermined pressure differential isreached in the cylinder to insure that the ball valve moves from theclosed to the open position without lingering at an intermediatepositionp The detent assembly 380 comprises a plurality of colletlingers 381 formed on and extending outwardly from the annular piston353 with the inwardly extending bosses 382 being engageable over thesplit lock ring 383 `positioned in the external annular recess 384around the valve seat body 335. The collet fingers are l-aterallyflexible so that when the piston moves to the lower end of its strokethe bosses engage the lock ring causing the collet fingers to springoutwardly until the bosses have passed the lock rngwhen the fingersspring inwardly to lock the lingers over the lock rin'g thus holding thepiston at its lowermost position until the pressure within the cylinder375 is raised to a sufiiciently high level to disengage the collet-ngers and allow the piston to be forced upwardly. The pressure at whichdisengagement of the piston is effected is determined by the pressurenecessary to move the pistons and ball valve completely from oneposition to another position without the valves lingering between suchpositions.

The detent assembly 392 at the other end of the valve includes thecollet fingers 393 extending outwardly and radially positioned aroundthe annular piston 354. Each of the detent fingers has an inwardlyprojecting boss 394 engageable over the split lock ring 395 positionedin the external annular recess 396 around the valve seat body 340. Thecollet fingers are illustrated in FIGURE 11 engaged over the` lock ringholding the piston in the upper position at the upper end of its stroke.When the pressure is raised to a predetermined level in the cylinder390, the collet fingers will be cammed outwardly by the lock ringdisengaging the fingers fromthe lock ring to permit the piston to beforced downwardly. The colletv fingers hold the piston in the upperposition until the pressure is high enough to fully displace the pistondownwardly to move the ball valve from the illustrated position to theother position at which the valve ow passage connects with the flowpassage 350.

As illustrated in FIGURE l1, the ball valve 341 is positioned to allowfluid flow between the conduits 311 and 313 through the bore 345, theflow passage 350, and the ports 351 in the tubular housing 314. So longas the pressure within the bore 345 is maintained higher than thepressure within the bore 350 the valve will remain in the positionillustrated permitting fluid flow in either direction between theconduits 311 and 313. The pressure in the bore 345 may result from ahigher pressure in either or both of the conduits 311 and 313. When itis desired to move the ball valve from the posi- .tion illustrated to asecond position interconnecting the conduits 312 and 313, the pressurewithin the conduit 312 is raised above the pressure within the conduits311 and 313 a sufiicicnt amount to displace the annular piston 354toward the ball valve to rotate the ball valve degrees to a position inwhich the fiow passage 350 is encompassed by the valve seat 343 toconnect the flow passage with the bore 350. The pressure within the bore350 is applied through the radial ports 391 into the annular cylinder390 against the outward end of the annular piston 354. Through the ports376 the pressure within the bore 345 is imposed on the outward end ofthe annular piston 353 and since this pressure is lower thanthe-pressure within the annular cylinder 390 the pressureu differentialacross the opposite ends of the interconnected pistons causes both ofthe pistons along with the operator members 352 to move downwardlyrotating the ball valve from the position shown to the second positioninterconnecting the conduits 312 and 313. In raising the pressure withinthe annular cylinder 390 the detent assembly 392 retains the annularpiston in the position shown until a predetermined pressure level isreached which is sufliciently high to cause the pistons, the operatormembers, and the valve to move sufficiently to shift the valve to thedesired position without lingering at an intermediate position whichwould place the flow passage 360 in communication With both of the bores344 and 345 simultaneously. When the annular pistons reach the other endof their travel path the detent mechanism 380 engages the annular piston353 to hold the piston in the downward position until movement of theValve is again desired by raising the pressure within the annularcylinder 375. When the ball valve is at either of the open positions,the higher pressure within the fiow passage 344 and around the outersurfaces of the valve exposed to the fluid flowing between the twoconduits which are interconnected biases the ball valve toward the seaton the valve body associated with the conduit which is closed off andtherefore leakage is minimized from the communicating conduits into theconduit which is closed.

It will now be seen that there has been described and illustrated a newand improved fluid flow control apparatus for selectivelyinterconnecting a plurality of zones in response to pressuredifferentials established between communicating and noncommunicatingzones.

It will be further seen that there has been described and illustrated anew and improved valve assembly for connection between three pressuresources with the first pressure source being selectively connectable tosecond and third pressure sources while the second and third pressuresources are not connectable with each other.

It will also be seen that operation of the valve may be initiated fromthe second and third pressure sources to selectively connect each of thesources with the first pressure source but operation of the valve is notinitiatable from the first pressure source.

It will additionally be seen that there is provided a valve assemblywhich selectively connects either of the second and third pressuresources with the first pressure source by initiating valve action fromeither of the second and third pressure sources and which subsequent toconnection between the desired two pressure sources will remain open solong as a predetermined pressure differential is maintained to permit astate of either no flow between the connected sources or flow in eitherdirection between the sources.

It will additionally be seen that one form of Valve assembly accordingto the invention includes interconnected plug type valves reciprocablebetween four positions for interconnecting a first pressure zone witheither of second and third pressure zones or prohibiting all flowbetween any of such pressure zones.

It will also be seen that another form of valve assembly according tothe invention includes two rotatable ball valves between a central flowpassage end connecting first and second flow passages. The ball valvesbeing rotatable to connect the control flow passage with either of theother fiow passages but not to connect the other fiow passages with eachother.

It will additionally be seen that a further form of valve according tothe invention includes two ball valves each of which is independent ofthe other and spring biased toward a closed position while the valvesare rotatable in response to movement of a flange on a reciprocabletubular type operator piston encompassing both of the valves.

It will also be seen that another form of a valve according to theinvention includes two ball valves interconnected with each other sothat one ball valve is in an open position while the other is in closedposition, such relative positions being reversed upon rotation of thevalves by a common interconnecting operator member actuated by pressureresponsive pistons exposed to the pressure in two zones which areconnectable with another zone by the valve.

It will be further seen that another form of valve according to theinvention includes .a single rotatable ball valve positioned between twotubular seat bodies and rotatable by an interconnected pressureresponsive annular piston between a first position for connecting afirst pressure zone with a second pressure zone to a second position forconnecting the first pressure zone with a third pressure zone.

The foregoing description of the invention is explanatory only, andchanges in the details of the construction illustrated may be made bythose skilled in the art, within the scope of the appended claims,without departing from the spirit of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. Apparatus for cont-rolling fluid fiow [between a plurality of zonescomprising:

a housing having a bore and a plurality of fiow openings into said bore,one from each of said zones; valve means in said housing coacting withsaid openings and movable between a plurality of positions forinterconnecting selected groups of said openings from said zones; andvalve means actuating means operable in response to the pressure in oneof said zones of a selected group for moving said va-lve means to oneposition closing ofi one of said openings and interconnecting the otheropenings, and operable in response `to the pressure in one olf the zonesof another selected group of said zones for moving said valve means toanother position closing off a second one of said openings andinterconnecting the other openings; said Valve means being constructedto prevent fow communication between said one opening and said secondopening; Isaid valve means actuating means being operable in response tothe pressure in said one zone and said second zone in excess of thepressure in said third zone for moving said valve means to a positionsimultaneously communicating said one zone and said second zone withsaid third zone and operable to prevent flow between said one zone andsaid second zone.

2. Apparatus for controlling fluid ow between a plurality of zonescomprising: :a housing having a bore and a plurality of flow openingsinto said bore, one from each of said zones; valve means for selectivelyinterconnecting a first of said zones with a second and a third of saidzones and for preventing fiuid communication between said second zoneand said third zone; valve actuating means connected ywith said valvemeans and operable in response to the pressure 'within said second zonefor moving said valve means to a first position interconnecting saidfirst zone and said second zone and preventing communication betweensaid third zone and said second zone; valve actuating means connectedwith said valve means and operable in -response to the pressure withinsaid third zone for moving said valve means to a second positioninterconnecting said first zone and said third zone and preventing fluidcommunication fbetween said second zone and said third zone; and meanscoacting with said valve means and operable in response to pressures insaid second zone and in said third zone in excess of the pressure insaid first zone for moving said valve means to a position simultaneouslyinterconnecting said second zone and said third zone with said firstzone to permit simultaneous fiow between said second zone and said rstzone and between said third zone and said first zone and operable tomove said valve means to prevent flow between said second zone and saidthird zone.

3. A valve -for selectively controlling fiuid ow between a first zoneand second and third zones comprising: valve housing means; means-associated with said valve housing means tor permitting fiuid flowbetween said housing means and said first zone; means associated withsaid housing means for permitting fluid fow between said housing means.and said second zone; means associated with said housing means [forpermitting fluid fow between said housing means and said third zone;valve means positioned within said housing means and coacting with saidmeans permitting fiow between said second zone and said housing forcont-rolling fitow therethrough and coacting with said means permittingfiow between :said third zone and said housing for controlling flowtherethrough, said valve means being pressure responsively movable to afirst position for permitting fluid flow between said first zone andsaid second zone while prohibiting fluid flow between said first zoneand said third zone and between said second zone and said third zone;and said valve means being pressure responsively movable to a secondposition permitting fiuid flow Ibetween said first zone and said thirdzone while prohibiting fluid fow between said first zone and said secondzone and between said second zone and said third zone; and meanscoacting with said valve means and operable in lresponse to pressures insaid second zone and in said third zone in excess of the pressure insaid first zone for moving said valve means to a position simultaneouslyinterconnecting said second Zone and said third zone with said firstzone to permit simultaneous flow between said second zone and said firstzone and between said third zone and said first zone and `operable tomove said valve means to prevent flow between said second zone and saidthird zone.

4. A valve for controlling fluid fiow between a first zone and secondand third zones comprising: valve housing means provided with meansforming a fiow passage to said first zone, a ow passage to said secondzone, and a flow passage to said third zone; valve means supportedwithin said housing means, said valve means coacting with said flowpassages leading to said second and said third zones for controllingflow into said housing means from said second zone and said third zoneand prohibiting fiuid flow between said second and third zones, saidvalve means being movable between a first position permitting fiuid fiowthrough said iiow passage leading to said second zone into said housingmeans while closing said flow passage leading from said housing means tosaid third zone and a second position opening said flow passage leadingfrom said housing to said third zone while closing said fiow passageleading from said housing means to said second zone, said valve meansbeing operable to move between said first and said second positions inresponse to pressure differentials 1between said second and said thirdzones, said valve means being retainable in either of said positionsafter 4being moved to said positions by a pressure differential betweensaid housing means and the flow passage closed by said valve means insaid position; and means coacting Iwith said valve means and operable inresponse to pressures in said second zone and in said third zone inexcess of the pressure in said first zone for moving said valve means tola position simultanesously interconnecting said second zone and saidthird zone with said first zone to permit simultaneous flow between saidsecond zone and said first zone and between said third zone and saidfirst zone and operable to move said valve means to prevent flow betweensaid second zone and said third zone.

5. A valve for controlling fluid flow between a irst zone and second andthird zones comprising: valve housing means provided with means forminga liow path to said first zone, a ow path to said second zone, and aflow path to said third zone; valve means within said housing means,said Valve means coacting with said flow paths leading to said secondand third zones for controlling ow from said zones into said housingmeans and prohibiting ow between said second and third zones; -saidvalve means being movable between a first position interconnecting saidhousing means and said liow path leading to said second zone whileclosing said flow path leading to said third zone; said valve means-being movable to a second position interconnecting said fiow pathleading to said third zone and said housing means while closing saidilow path leading from said housing means to said second zone; andreciprocable valve operator means exposable at one end to the pressurein said path leading to said second zone and exposable at the other endto the pressure in said path leading to said third zone, said operatormeans being movably responsive to pressure differentials between saidsecond and third zones for moving said valve means between said firstand said second positions; said valve operator means 4being operable inresponse to pressures in said second zone and in said third zone inexcess of the pressure in said first zone for moving Vsaid valve meansto a position simultaneously interconnecting said second zone with saidfirst zone and said third zone with said first zone and operable toprevent iiow between said second zone and said third zone in eitherdirection.

l6. A valve for controlling uid flow between a first zone and second andthird zones comprising: housing means; said housing means being providedwith means forming a ilow path to said first zone, with means providinga tiow path to said second zone, and with means providing a flow path tosaid third zone; valve means coacting with said flow path leading tosaid second zone for opening and closing said flow path; valve meanscoacting with said ow path leading to said third zone for opening andclosing said ow path; support means slidably extending through each ofsaid valve means for supporting each of said valve means as each of saidvalve means moves between an open and a closed position; and biasingmeans associated with each of said valve means and said support meansfor biasing each of said valve means toward a closed position.

7. A valve for controlling fluid iiow between a first zone and secondand third zones comprising: a valve housing provided with a port leadingto said first zone; means associated with said housing forming `a flowpassage leading to said second zone, said means including an annularvalve seat surrounding said fiow passage; means associated with saidhousing providing a flow passage leading to said third zone, said meansincluding yan annular valve seat around said liow passage; a first valveengageable with said valve seat around said flow passage leading to saidsecond zone; -a second valve engageable with said valve seat around saidflow passage leading to said third zone; a valve rod extending inslida-ble relationship through said rst valve and said second valve topermit each of said valves to move laway from its respective valve seat;to 'an open position and to -support each of said valves while in saidopen position; and a spring disposed around said rod between andengageable with said valves for biasing each of said valves toward aclosed position.

8. A valve for controlling liuid fiow between a iirst zone and secondand third zones comprising: a valve housing having means providing aport leading to said first zone; means lassociated with said housingproviding `a flow passage to said second zone and a lvalve seat formedyaround -said flow passage; means associated with said housing providinga ow passage to said third zone and a valve seat surrounding said flowpassage; said valve seats being spaced apart from each other along a alongitudinal axis of said housing; a first valve engageable with one ofsaid valve seats to control fluid flow through the passage associatedtherewith; a second val-ve engageable with the other of said valve seatsfor controlling the fluid flow through the passage associated with saidvalve seat; a valve rod extending through each of said valves andslidable relative to said valves for maintaining said valves inalignment with said seats `andsupporting each of said valves when inopen position; and a spring around said valve rod between and inengagement with said valves for biasing said valves away from each othertoward a closed position, said valves prohibiting flow between saidsecond and third zones.

9. A valve in accordance with claim 8 including in addition thereto ahead member on opposite ends of said valve rod for retaining said valveson said rod.

10. A valve in accordance with claim 9 including seal means within eachof said valves around said rod for seating between each valve and saidrod to prevent fluid leakage along said rod through each of said valves.

11. Apparatus for controlling iiuid flow between a plurality of zonescomprising: a housing having a bore and a plurality of ow openings intosaid bore, one from each of said zones; valve means in said housingcoacting 'with said openings movable between a plurality of positionsfor interconnecting selected groups of said openings from said zones;valve means actuating means operable in response to the presence in oneof said zones of a selected group for moving said Valve means to oneposition closing off one of said openings and interconnecting the otheropenings, and operable in response to the pressure in one of the zonesof another selected group of said zones for moving said valve means toanother position closing off a second one of said openings andinterconnecting the other openings, said valve means being constructedto prevent fiow communication between said one opening 'and said secondopening at all times; and second valve means actuating -means operablein response to the pressure in a third one of the .zones other than saidone zone and said second zone for moving said -valve means to a positionsimultaneously closing off the openings to both said one zone and saidsecond zone.

12. Apparatus for controlling fluid flow between a plurality of zonescomprising: a housing having a bore and a plurality of iiow openings insaid bore, one from each of said zones; valve means in said housingcoacting with said openings for selectively interconnecting a first zoneand a second zone with a third zone; means operable in response to thepressure in the second of said zones for moving of said valve means toone position closing off the opening to said first zone andcommunicating the openings to said second and said third zones; meansoperable in response to the pressure in the first of said zones formoving said valve means to another position closing off the opening tosaid second zone and communicating the openings to said lirst and saidthird zones, said valve means having means providing for movement ofsaid valve means to close off flow communication between said openingsto said lirst zone and to said second zone at all times; and meansresponsive to pressure in said third zone for moving said valve means toa position simultaneously closing ofi both the opening to said firstzone and the opening to said second zone.

13. Apparatus of the character set forth in claim 12, and meansresponsive to pressures in said first zone and said second zone inexcess of the pressure in said third zone for moving said valve means toa position simultaneously fiow communicating both said first zone andReferences Cited STATES PATENTS Fitch 137-112 Hollerth 137-113 Audemar137-112 said second zone `with said third zone and operable to preventHow between said rst zone and said second zone.

20 2,680,016 6/1954 McLeod 137-112 XR 2,764,175 9/1956 Mericer 137-118XR 3,008,481 11/1961 Matheson ALAN COHAN, Primary Examiner.

WILLIAM H. WRIGHT, Assistant Examiner.

U.S. C1. X.R. 137-111, 627.5

